SQL_查询当天、近几天、本周、本月的SQL语句

经常会有时候要用到查询当天，近几天，本周，本月的相关数据，所以记录一下这些比较特殊的SQL语句~~
--当天
(usrRegTime >=CONVERT(varchar(10),getDate(),120)+' 00:00:00' and usrRegTime <=CONVERT(varchar (10),getDate(),120)+' 23:59:59')
--近三天
DateDiff(day,usrRegTime,getdate()) <=3
--本周
Datepart(year,usrRegTime)=DatePart(year,Getdate()) and DatePart(week,usrRegTime)=DatePart (week,GetDate())
--本月
Datepart(year,usrRegTime)=DatePart(year,Getdate()) and DatePart(month,usrRegTime)=DatePart (month,GetDate())